Heat exchanger



G. H. YOUNG HEAT EXCHANGER Oct. 17, 1944.

Filed March 28, 1942 I 2200922302 650265 6 J/OUAK;

viii-2302 2283 Patented Oct. 17, 1944 UNITED STATES PATENT OFFICE HEAT EXCHANGER George HtYoung, Indianapolis, Ind., assignor to B. F. Sturtevant Company, Boston, Mass,

Application March 28,1942, Serial No. 435,567

supplyunheated air 'intothe fans as will be de- 4 Claims.

This invention relates to heat exchangers for varying the temperature of air and has as its object the accurate control of the effect of the heat exchangers whereby more uniform air temperatures may be maintained.

The usual method of controlling the effect of heat exchangers such, for example, as unit heaters, is to damper the air from the heater for decreasing the heated air volume when less heat is required, and for increasing the heated air volume when more heat is required. A disadvantage of this method is that the volume of air recirculated is not uniform.

This invention provides for varying the volume of heated air from a unit without varying the total volume of air which is delivered by the unit.

In a preferred embodiment of the invention a two inlet fan has one inlet connected to draw air through a heater, and the other inlet arranged to draw in unheated air. The outlet of the fan discharges into the space to be heated. Spin inducing vanes are placed in each inlet. When less heat is required, the vanes in the inlet connected to the heater are adjusted towards closed position while the vanes in the other inlet are conformably adjusted towards open position. The fan thus While delivering a constant volume of air, delivers smaller volumes of heated air when less heat is required, and delivers greater volumes of heated air when more heat is required.

The invention will now be described with reference to the drawing, of which:

Fig. 1 is a side elevation of an air heating unit embodying this invention, and

Fig. 2 is a sectional view taken along the lines 2-2 of Fi 1.

The unit 5 has a plurality of parallel vertical rows of circular finned tubes 6. The tubes are connected as shown in Fig. 2 to an upper header l and to a lower header 8 for the supply of a Heating fluid which, for example, may be steam.

The unit 5 is supported at its opposite ends by the transformation plates 9 from the centrifugal fans Ill. The plates 9 also form converging outlets from the unit 5, connecting the inner inlets El of the fans with the interior of the unit.

The centrifugal fans lll illustrated are similar to that disclosed in the Hagen Patent No. 1,989,-

413 except that the bearings l2 thereof are supported similar to the fan bearings disclosed in the Bartlett and Leonard Patent No. 2,113,391.

The fans Hl also have the outer inlets it which are open to the atmosphere and which serve to scribed.

p The inlets l l of the fans contain the spin vanes M which are rotated through the up and down movement of the arms 15 and I6 which cause rotation of gears in the gear assemblies indicated generally by I1 as disclosed in detail in said'I-Iagen patent. The inlets l3' of the fans contain similar spin vanes which are rotated through the up and down movement of the arms [5 and I8 which cause rotation of gears inthe gear assemblies l'l associated with the vanes ll in the inlets l3.

The arms l6 which serve to adjust the vanes M in the inlets II and the arms l8 which serve to adjust the vanes l4. in the inlets l3, are secured to the rock shaft l9 which in turn is arranged to be rotated through an angle of 180 by the piston 20 connected to theplunger armature N of the solenoid 22. I

The winding of the solenoid 22 is connected in series with the thermostat 23 and a suitable electric source.

The arms [8 are placed apart on the shaft 19 with respect to the arms l6 so that as illustrated by Fig. 1 the arms ii! are almost in their lowermost position with the vanes l4 associated therewith almost fully open, while the arms l6 are almost in'their uppermost position with the vanes l4 associated therewith almost fully closed.

The action of the spin vanes I4 is disclosed fully in the Hagen Patent No. 1,846,863 and it is believed to be sufficient to state here that as the vanes are rotated towards their closed position, the air volume through the fan inlet in which they are placed, decreases conformably with the rotation Of the vanes, and when they are rotated towards their open position, the air volume through them increases conformably with their rotation.

In operation, when the thermostat 23 calls for heat it energizes the solenoid 22 and causes it to rotate the shaft l9 and the arms l6 and i8 and through them to adjust the vanes l3 in the inlets l3 towards closed position, and the vanes M in the inlets ll towards open position. This causes less unheated air to be drawn in through the inlets l3 and more air to be drawn in through the inlets ll connected to the heater 5. Conversely when the thermostat 23 calls for less heat, the spring biased solenoid 22 rotates the shaft IS in the other direction causing the arms l6 and I8 to adjust the vanes so that more unheated air is drawn in through the inlets l3, and less heated air through the inlets ll.

The dampers which previously have been used for controlling air volumes, in addition to varying the volume of delivered air. have caused power losses due to the air resistance they introduce.

The spin vanes utilized in this invention not only enable a constant air volume to be delivered but they offer substantially no resistance to the air and causing therefore practically no power losses. A constant speed motor may be used for driving the fan at constant speed for delivering unchanged air volumes throughout the range of adjustments.

The thermostat 23 and solenoid 22 may be of the graduated type affecting graduated adjustment of the spin vanes, or they may be of the onoif type for completely closing the vanes in one pair of'inlets While completely opening the vanes in the other. pair of inlets.

The thermostat 23 and the solenoid 22 may be omitted and manual adjustment of the vanes provided by means of the crank 24 at one end of the shaft l9.

While fans have been illustrated as being placed at opposite ends of the unit 5 for drawing air therethrough in both directions, one fan may be omitted and the end of the unit 5 to which it is shown connected may be closed.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated as modifications thereof may be suggested by those skilled in the art without departure from the essence of the invention.

What is claimed is:

1. A heat exchanger for supplying tempered air to a space, comprising a heat exchange surface, a constant speed fan having two inlets and an outlet, means connecting one of said inlets with said surface and providing a passage for air drawn through said surface and said one inlet into said fan, the other of said inlets connecting with said space, and means including spin vanes in said inlets for increasing the volume of air through one aseasse of said inlets and for simultaneously decreasing the volume of air through the other of said inlets, for varying the temperature of the air from said outlet.

2. A heat exchanger for supplying tempered air to a space, comprising a centrifugal fan having opposed axial inlets and an outlet, an annular heat exchange surface in axial alignment with and connected to one of said inlets, the other of said inlets connecting with said space, and means including spin vanes in said inlets for increasing the volume of air through one of said inlets and for simultaneously decreasing the volume of air through the other of said inlets, for varying the temperature of the air from said outlet.

3. A heat exchanger for supplying tempered air to a space, comprising an annular heat exchange surface, a pair of centrifugal fans having opposed axial inlets and an outlet, said fans being arranged in axial alignment with said cylinder, one at each end thereof and each having its inner inlet connected to the adjacent end of said surface, for drawing air through said surface into said fans, the outer of said inlets connecting with said space, and means for increasing the volume of air through said inner inlets and for simultaneously decreasing the volume of air through said outer inlets.

4. A heat exchanger for supplying tempered air to a space, comprising an annular heat exchange surface, a pair of centrifugal fans having opposed axial inlets and an outlet, said fans being arranged in axial alignment with said cylinder, one at each end thereof and each having its inner inlet connected to the adjacent end of said surface, for drawing air through said surface into said fans, the outer of said inlets connecting with said space, and means including spin vanes in said inlets for increasing the volume of air through said inner inlets and for simultaneously decreasing the volume of air through said outer inlets.

GEORGE H. YOUNG. 

